A Supra-galactic Conundrum: The Globular Clusters Colour Pattern in Virgo Galaxies

FORTE, JUAN C; CELLONE, SERGIO A; DE ROSSI, MARÍA E; ESCUDERO, CARLOS; FAIFER, FAVIO R; GEISLER, DOUGLAS; GONZÁLEZ, NÉLIDA M; SCALIA, MARÍA C; SESTO, LEANDRO; CASTELLI, ANALÍA V SMITH; IRENE VEGA, E

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2019 vol. 482 p. 950 - 964

0035-8711

 The presence of systematic modulations in the colour distributions in composite samples of globular clusters associated with galaxies in the Virgo and Fornax clusters has been reported in a previous work. In this paper we focus on the 27brightest galaxies in Virgo, and in particular on N GC 4486, the dominant system in terms of globular cluster population. The new analysis includes ≈ 7600 cluster candidates brighter than g=24.5 (or T1≈ 23.70). The results indicate the presence of the characteristic Virgo pattern in these galaxies and that this pattern is detectable over a galactocentric range from 3 to 30 kpc in N GC 4486. This finding gives more support to the idea that the pattern has been the result of an external, still not identified phenomenon, capable of synchronizing the cluster formation in a kind of viral process, and on supra-galactic scales (also having, presumably, an impact on the overall star formation history in the entire Virgo cluster).